The field of the invention relates to lighted display signs, and, in particular, lighted display signs of the discharge type with interchangeable parts in order to create different messages.
The most common lighted display signs are neon signs which use a controlled, glowing discharge through inert gases. Most display signs utilize translucent tubing having a tortuous path forming a message or design. Other lighted displays are produced without translucent tubing, using multiple flat sheets assembled with a tortuous path interior of the sheets hermetically sealed with a rare gas, such as neon. U.S. Pat. Nos. 4,584,501, 4,839,555 and 4,887,003 describe the use of multiple sheets with a tortuous path filled with rare gases connected to a discharge to excite the gases, producing a display sign. Generally, the front sheet is transparent to emit light and the rear sheet is mirrored to reflect light toward the front sheet.
The prior art lighted display signs all present the same type of display sign where an entire message is displayed as a unit. The problem with such an arrangement is, should one of the electrodes break down or should the tortuous path leak, the entire sign has to be repaired. Some signs, like old transparent tubing signs, may require a lot of down time for repairs, particularly if a section of tubing has to be replaced. The solution is to provide a lighted display sign where an entire defective area can be removed and replaced in a short time. The present invention provides such a solution. Also, the prior art devices cannot be mass produced.